chore: copy script/patch.py from the libcc repo (#14627)

* chore: copy script/patch.py from the libcc repo

* chore: fix pylint errors

script/patch.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python
+"""
+Usage: patch -h
+
+Use this script to selectively apply and reverse patches.
+It is mostly useful to fix patches during upgrades to a new Chromium version.
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+
+import lib.git as git
+from lib.patches import Patch, PatchesList, PatchesConfig
+
+
+def main():
+  args = parse_args()
+
+  directory = args.directory
+  force = args.force
+  patches = args.patch
+  project_root = args.project_root
+  repo = args.repo
+  reverse = args.reverse
+
+  if directory:
+    (success, failed_patches) = apply_patches_from_directory(
+        directory, project_root, force, reverse)
+  else:
+    (success, failed_patches) = apply_patches(repo, patches, force, reverse)
+
+  if success:
+    print 'Done: All patches applied.'
+  else:
+    failed_patches_paths = [p.get_file_path() for p in failed_patches]
+    print 'Error: {0} patch(es) failed:\n{1}'.format(
+        len(failed_patches), '\n'.join(failed_patches_paths))
+
+  return 0 if success else 1
+
+
+def apply_patches(repo_path, patches_paths, force=False, reverse=False):
+  absolute_repo_path = os.path.abspath(repo_path)
+  patches = [Patch(os.path.abspath(patch_path), absolute_repo_path)
+             for patch_path in patches_paths]
+  patches_list = PatchesList(repo_path=absolute_repo_path, patches=patches)
+  stop_on_error = not force
+  return patches_list.apply(reverse=reverse, stop_on_error=stop_on_error)
+
+
+def apply_patches_from_directory(directory, project_root,
+                                 force=False, reverse=False):
+  config = PatchesConfig.from_directory(directory, project_root=project_root)
+  patches_list = config.get_patches_list()
+
+  # Notify user if we didn't find any patch files.
+  if patches_list is None or len(patches_list) == 0:
+    print 'Warning: No patches found in the "{0}" folder.'.format(directory)
+    return (True, [])
+
+  # Then try to apply patches.
+  stop_on_error = not force
+  return patches_list.apply(reverse=reverse, stop_on_error=stop_on_error)
+
+
+def parse_args():
+  parser = argparse.ArgumentParser(description='Apply patches to a git repo')
+  parser.add_argument('-f', '--force', default=False, action='store_true',
+                      help='Do not stop on the first failed patch.')
+  parser.add_argument('--project-root', required=False,
+                      default=git.get_repo_root(os.path.abspath(__file__)),
+                      help='A folder to resolve repos relative paths against')
+  parser.add_argument('-R', '--reverse', default=False, action='store_true',
+                      help='Apply patches in reverse.')
+  parser.add_argument('-r', '--repo', help='Path to a repository root folder.')
+
+  paths_group = parser.add_mutually_exclusive_group(required=True)
+  paths_group.add_argument('-d', '--directory',
+                           help='Path to a directory with patches. \
+                           If present, -p/--patch is ignored.')
+  paths_group.add_argument('-p', '--patch', nargs='*',
+                           help='Path(s) to a patch file(s).')
+
+  args = parser.parse_args()
+
+  # Additional rules.
+  if args.patch is not None and args.repo is None:
+    parser.error("Repository path (-r/--repo) is required \
+                 when you supply patches list.")
+
+  return args
+
+
+if __name__ == '__main__':
+  sys.exit(main())